Although the drum set is a "new" instrument, less then 100 years old, it has been a major contributor to the sound and evolution of a lot of music. Tomorrow's drummer will need to be familiar with the stylistic subtleties of every genre from Ragtime to Bebop to Drum' Bass and beyond. First and foremost, one must love music to the degree that they are willing to spend years in the woodshed developing the building blocks for a career:
Technique:
hands, coordination, concentration, reading
Groove:
the ability to play different feels, in a variety of tempi, in sync with a bass player
Musicianship
the ability to play in a way that enhances an ensemble's sound
Listening to the playing of great musicians is both enlightening and inspiring and contributes greatly towards learning what to practice and what to play.
Remember, that a drummer's role in a band is to provide a steady pulse, in the appropriate style, to help the ensemble sound like a polished unit by playing in a way that helps the band navigate through their more syncopated passages, to lead the band through the various dynamic changes in a piece.